Creped thermoplastic nonwoven materials are known from U.S. Pat. No. 4,810,556, issued to Kobayashi et al. In the disclosed process, a raw nonwoven fabric is coated with a lubricant and then pressed between a drive roll and a plate having a rough sandpaper-like surface. The plate is positioned near the drum and is substantially parallel or tangential to the outer surface of the drum. The raw nonwoven fabric is crinkled in a wavelike fashion in the direction of movement of the fabric by the frictional force caused by the pressing. The resulting creped fabric has wavelike crepes which contribute to softness. However, the creping accomplished by this process is not believed to be permanent. It is believed that the creping accomplished by this process can be removed or reduced significantly by subjecting the nonwoven web to mechanical stretching sufficient to flatten out the wavelike crepes. Also, the creping is naturally reduced over time during use of the fabric.
The creping of paper is also known in the art. However, paper has traditionally been creped using processes different from those used to crepe thermoplastic nonwoven webs. U.S. Pat. No. 3,879,257, issued to Gentile et al., discloses a process used for producing creped paper. A bonding material, preferably elastomeric, is applied to first and second surfaces of the paper so that it covers from about 15-60% of both paper surfaces and penetrates into about 10-40% of the paper thickness from both surfaces. Then, one side of the paper is adhered to a creping surface, such as a creping drum, using the bonding material to cause the adhesion. Then, the paper is creped from the creping surface using a doctor blade positioned at an angle to the surface. This creping method greatly disrupts the fibers in the unbonded regions of the paper increasing the overall softness, absorbency and bulk of the paper, and finely crepes the bonded areas of the paper to soften them.
There is a need or desire for a creped thermoplastic nonwoven web in which some or portions of the fibers are greatly disrupted to cause permanent creping. There is also a need or desire for a permanently creped nonwoven web containing individual filament loops, suitable for use as the female component in a hook-and-loop fastener. Furthermore, there is a need or desire for a permanently creped nonwoven web suitable for use as a liner, which has a hydrophobic side and a hydrophilic side.